Yellow azo dye and process of making same.



MELCHIOR BONIGER, oa sasiinswi'rzeamnn, ASSIGNORITO THE CORPORATION OF] CHEMICAL WORKS, FORMERLY sANDoz, OF'BASEL, SWITZERLAND-.1

YELLOW AZO DYE AND. PROCESS 0f MAKING- SAIE.

Speci fliiation of Letters Patent.,

Patented Oct. 20, 1908.

Application filed June 11, 1908. Serial 1%. 437,964.

To all wh0m lit may concern. 1

Be it known that I, MELCHIOR 'BONIGER doctor of philoso hy, chemist, a citizen oithe Swiss Repub 1c, and resident of Basel,

Switzerland, with the post-'oflice address Fabrikstrasse 116, have invented new and useful Improvements in new Yellow Azo Dyes and Rrocesses of Producing the Same, of wh ch the following is a specification.

This invention relates to the manufacture of yellow azo dyes .by combining pyrazolone compounds of the general formula wherein R stands for CH or COOH, with 'ters can be obtained in using the diazo compounds of the different anilincarboxylio the diazo compounds of anilincarboxylic acids, anilinsulfonic acids, their homologues and halogen derivatives. The coloring matters so obtained dye wool from an acid bath bright yellow shades, which are distinguished by their excellent fastnessto light.

On account of this property they are alsoparticularly suitable for the preparation of lakes. I V

The newcoloring matters which l-desire to claim generally-arecharacterized by the following properties: They form yellow powders, easily soluble'in water with yellow color, which is not altered'by the addition of acids.

rapidly red-violet. T In strong sulfuric acid they dissolve with a greenish-yellow colora- The method ofproduction is illustrated by the following examples cined sodium carbonate in about 600 liters of water at a temperature not exceedin 10 C.

the diazosulfonic acid obtained in t a well known manner from 34.6 kg. metanilic Their neutral watery solution boiled with zinc dust is decolorize'd,'thesolution becoming, in contact with the air acid. After stirring for an hour precipitate the dyestufi from the intense greenish-yellow solution by addition of common salt. When filtered and dried it forms a clear yellow powder; it dyes Wool from an acidulated bath in greenish yellow tints exceedingly fast to light.

Example II. Introduce into a solution of,

73 k l -orthometadichlorparasulfophenyl-3- 'methyl-5-pyrazolon and 40 kg calcined sodium Oarbonat ein about 600 liters of water at 10 C. the 4ediazo-L3-xylol-5-sulfonicacid obtained from402 kg. metaxylidinesulfonic acid. Stir for an hour, then heat to Y the boil and preci'pitate the dyestuff by addition of common salt and a mineral acid until weakly acid reaction is reached. It dyes -wool from an aeidulated bath-in brilliant yellow shades of extraordinary fastness against the action of light.

In a similarmanner yellow coloring matacids, analinsulfonic acids, their homologues and halogen derivatives for the'combination with the pyrazolone compounds hereinbefore mentioned.

Now what I aim and desire to secure by.

Letters Patent is the following:

1. The herein described process for the manufacture of yellow azo dyes by combinwherein R stands for CH or COOH, with the diazo comfpounds of anilincarboxylic their homologues acids, anilinsul onic acids, and halogen derivatives.

2. The yellow'coloring mattersobtained Y ing in an alkaline solution a pyrazolone compound of the formula p Y as- 'hereinbefore described, being in dry state yellow powders, easily soluble in water with ellow' color, which'is not altered by the a dition of acids, dissolving in concen- 2 o V sown trated sulfuric acid with a greenish-yellow Kfesence of two Witnesses; this, 25th day of coloration, their neutral Watery solution boiled with zinc dust bein decolorized, the

solution thereby obtained ecoming in con- 5 tact with the an rapidly reddish violet. VVitnesse's:

In testimony, that I claim the foregoing ARNOLD STEINER,

as my invention, I-have signed my name in GEO. H.- WAGNER.

MELCHIOR BGNIGER. 

